Seacat first attracted attention—as Sandra Kaufman, her then married name—in July 1962, in the Barnard-Columbia Summer Theater production of Somerset Maugham's The Noble Spaniard. Despite finding the play "rather silly,” Back Stage's reviewer "found particular pleasure in Sandra Kaufman's characterization."[20] She appeared once more that summer, this time under Michael Howard's direction, in the US premiere of Leonid Andreyev's The Waltz of the Dogs.[21] Amidst a generally favorable review, Back Stage reserved "bouquets" for Kaufman and 2 others,[22] while The Village Voice predicted, “Miss Kaufman’s appetizing warmth [is] destined to bring many future stages alive.”[23]

The following winter, an eventful few hours—attaining both Actors Studio membership and first-time motherhood[24][25]—gave rise to roughly 2 years of seeming inactivity, a notable exception being Kaufman’s Broadway debut, a small part in the Actors Studio production of Chekhov’s Three Sisters.[1][26] Her full-fledged return came on October 12, 1965, in Atlanta’s Community Playhouse (again under Howard’s direction),[21] when, having beaten out Rosemary Forsyth for the title role in Shaw’s Saint Joan,[27] Kaufman's portrayal was hailed by The Journal-Constitution as "a masterpiece of suave speech and faultless timing [which] enhances the lyrical quality of Shaw's lines." "Kaufman," it continues, "is both saint and genius; her portrayal leaves nothing to be desired."[28]

Over the next decade, while teaching in New York and Los Angeles,[10] Seacat was credited with a number of such breakthroughs, including those of Jessica Lange,[37][38][39]Rachel Ward[40][38] and Marlo Thomas.[39][8] During this period, she also helped pioneer the practice of dream work, in which actors study and play characters from their dreams.[10] Among those studying the technique was Seacat's daughter, Greta, who went on to become an acting coach. In addition, actresses Melanie Griffith and Gina Gershon publicly credited Seacat's use of the dream method with improving their craft.[41][42]

Also attending those classes was future Songwriter's HOF inductee Desmond Child, then a self-professed "fly on the wall" alongside Lange, Rourke, Michelle Pfeiffer and others. Speaking in 2018 with Music & Musicians, he gratefully acknowledged Seacat's mentorship, noting the correlation between her early efforts at linking text to actor and Child's later knack for matching song to singer. Similarly, Child embraced Seacat's vision of the artist as a "wounded healer" and the audience "a co-creator [who] heals through that process." "As songwriters," Child concurred, "we have a sacred job to help them connect."[43]

While Seacat has always shunned publicity, both for her own sake and that of her clients,[50] she has gone on record regarding a few of her more famously self-proclaimed students such as Jessica Lange,[51] Mickey Rourke,[52]Meg Ryan[53] and, on multiple occasions, Laura Dern,[54][55] whose longstanding relationship with Seacat is the subject of a brief article and the accompanying video published by The Hollywood Reporter in February 2015.[14]

Seacat has directed one movie, In the Spirit, shot in 1988, released in April 1990, and starring Marlo Thomas and Elaine May. The year-plus gap between wrap and release saw one previously announced cast member, Louise Lasser, end on the cutting room floor,[57][58] as well as the addition of what Variety would later term "the stupid framing device of a mystical narrator,"[59] presumably inserted in hopes of patching over rough spots in the narrative, in particular the dramatic shift in tone occurring midway through the film.

That any such hopes had gone unrealized was the general consensus amongst critics, who were nonetheless divided between those who found such flaws forgivable—such as The Boston Globe ("An Endearing Mess")[60] or Hal Hinson of The Washington Post ("disjointed [but] deliciously addlebrained")[61]—and those who did not, such as Janet Maslin, who dubbed In the Spirit "a nervous new-age comedy more notable for good intentions than good luck,"[62] and the Los Angeles Times, which noted that what begins as "a richly comic" vehicle for Ms. May abruptly "crumbles around her at roughly its halfway point."[63]Variety, however, perceived a method to Spirit's messiness, "a throwback to the looser, madcap '60s," featuring "big name talent [working on] a low budget" to make a "pic freed of mainstream good taste and gloss."[59]

^Confusion about the spelling of Seacat's first name has arisen over the years, because of its counterintuitive pronunciation. Despite the conventional spelling, her name is properly pronounced somewhere between 'Sondra' and 'Saundra';[6] thus, on occasion, it has been misspelled accordingly, both in print and online.[7]

^Starting in 1968 (when her first marriage ended in divorce), Seacat has always worked under her maiden name.

^ abcdThomas, Marlo (2010). "Obsession". Growing Up Laughing: My Story and the Story of Funny. New York: Hyperion. p. 210. ISBN0-13-367870-9. I only wish Lee [Strasberg] could have lived to see me portray a schizophrenic in Nobody's Child. I never could have gotten near playing that kind of part without Lee's exercises, and the subsequent work I did and continue to do with his primary disciple, the brilliant Sandra Seacat.

Rosenbaum, Ron. "Jessica Lange: Sex and Subtext". Vanity Fair. October 1988. "She never worked with Strasberg, but she did work with one of his acting-teacher disciples, Sandra Seacat. 'She really changed things around for me. She got me at the moment where it was all beginning to come alive, and it was a great catalyst for me.' What was her method like? 'She was out of the Actors Studio, but then she really diverged from Method acting. She did a lot with Siddha yoga. You know, she was a follower of Guru Baba Muktananda. I never became a follower of his,' Jessica says, 'but Sandra brought a lot of that stuff into her early work with me, relaxation and meditation.'"

Rosenbaum, Ron. "Jessica Lange: Sex and Subtext". Vanity Fair. October 1988. "She never worked with Strasberg, but she did work with one of his acting-teacher disciples, Sandra Seacat. 'She really changed things around for me. She got me at the moment where it was all beginning to come alive, and it was a great catalyst for me.'

^ abSmith, Liz. "Elaine May gathers quality cast together for her next movie". The Orange County Register. December 1, 1988. "The director was an interesting choice: Sandra Seacat, acting coach and guru to many stars. (Sandra is credited with helping Jessica Lange to her Oscar and Marlo Thomas to her Emmy."

^Solomon, Linda Ilene (June 8, 1993). "A Vietnam Movie Through a Different Lens". International Herald Tribune. June 8, 1993. "Disenchanted with Hollywood and frustrated by the limited roles available for Shakespearean-trained Asian-American actresses, Alexandra took the advice of her acting teacher, Sandra Seacat, who told her she'd find 'all the power in the universe' in going back to her roots."

^ abSilverman, Jason. "Cine Cafe on Bender: Producer guests at CSF". The Santa Fe New Mexican. March 29, 1996. "A former member of Maine State Ballet, Bender began studying acting after a dance injury ended his career. He took classes with renowned coach Sandra Seacat, working with actors-in-training including Jessica Lange, Mickey Rourke, Mario Thomas and Christopher Reeve."

^ ab"Carter tackles the wonders of history". USA Today. August 15, 1994. "[S]he started commuting to New York to meet with acting coach Sandra Seacat, who also works with Melanie Griffith, Marlo Thomas and Tatum O'Neal. 'The experience was "better than any therapist,' she says. 'You strip yourself of ego, and the whole experience unearths all your analytical feelings and self-discovery.'"

^Galloway, Stephen. "Andrew Garfield on Mel Gibson: 'He's All Flesh and Blood and Passion'". The Hollywood Reporter. November 4, 2016. "GALLOWAY: Do you have an acting coach you work with? GARFIELD: Yeah, I do. I’ve worked with a couple of people that are actually mother and daughter. Sandra Seacat is the name of the mother, and Greta Seacat is the name of the daughter, and they’re both witches. They’re both just these genius witches."

^Ryan, Michael. “We All Have a Place We Feel Locked Out Of”. ‘’The Indianapolis Star’’. April 6, 1986. “Thomas' next move was unconventional if not downright audacious. In 1978, she simply stopped appearing in public. ‘I needed to go back to the beginning, so I took off and studied with Lee Strasberg and Sandra Seacat,’ she recalled.”